Flash-mold



W. H. KEMPTON.

FLASH MOLD.

APPLICATioN FILED sEPT.10,1911.

Patented Mar. 16,1920.

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-WILLARD nknivirroivgor wiLK-iNsBifi-RG, PENNSYLVANIA; iissiGNoR To wns'r- INGHoUsn niincraic AND MANn-riic'rnains .coi/iraNY, V.aY'conronnfiionfor n :PENNSYLVANIA Be fr "known thai, wma@ invented a new and useful Improvement'in' specification.

tus .and `particularly to Vmoldsofthe class :termed flash "inold'isfp and it" has for an `ob-.v

i ject to provide molding apparatus which will. permit'the escape of excessmoldingv material while insuring that .the molded v partsfare properly formed and completely filled out. .l c L A further object of my invention'isto provide molds in which the molded material.l

is subjected to a certain pressure 'durinfgjv molding in order to prevent flaws and holes.y

y LIn the drawing, Figurelis a cross sec-VV tion of the ordinary type of-lasli mold; 'Figf 2 is a cross-section of one form of iiiyl im` -y proved mold; and Fig.` 3 is a cross section` of a modified lform of niy invention.

The term flash mold, asfusedfherein, applies to that class of molds iii-lwhich an out or permitted to escape between" the two halves of themold during the molding op'-vv eration.

In Fig. 1 isshown the'ordinary two-part flash mold consisting-of upper or cope member 1 and lower or drag Vmember 2 which are kept in vertical alinenient vby pins 3 connected to the upper member 1 and fitting loosely into corresponding apertures 41 in the lower member 2. In molding or forming an object by means of this type of mold, an excess of the molten or plasticmaterial. to be molded is placed in the lower member and theV excess escapes between the g, two members, as at 5in Fig. 1,when tlievicope Vmember isk broughtr down upon "the drag member.

My improved form`` of mold is" shown in i Y Fig.-2, in which copemember 6 has, a down- `wardl'y extending flange 7 fitting` withinan upwardlyextending flange'8 onfdrag mem-r ber 9. AQclearance space 10 is provided between the flanges 7 and 8 through .which the excess material escapes. vDuring the molding operation, excess material flows out Y n Y jKiiiyI'r-"Qv TON, a citizenoflth'e United'States5v`andja1l resident ofVilkinsburg, in the countyf of AlleghenyT and State of,` Pennsylvania, have F lash-Molds,ofwhich` the following is a'.

rnAsrii-ivioiin:

l' .without opp-ositioinfas, cope member''.is'flow- Aered until 'theflowerfmargin-of Vflange 7] .passes the upper 'marginof lange"8.`Fron1 w Specification of Letters Patent. 16351920.' F f f j appiiatiiijfue septeate .10,1917. "serial"No.jie`o,oe}y: I

this point, therev isv an increasing vback Vpres- *If sure,- due to the headofinaterial in recess 10,"ias flange 7 travels downwardly, and

thisgback pressure tends *to resist the escape i p Y v ofi-material. This is very important in'fthati My invention relates to molding'apparait causes the material being moldedto prop-l 1u y erlyfill-fetichV portions oftlielmold V:as are most remote froinfthe points where .excess n ia-terial-k escapes. I

`In'tlie modification ofFig. 3, a cope niem-V A ber 11 lias'adownwardly-extending flange 12 'fitting within f upwardly-.extending flange `13 on drag member 1L1. v Flange 13 has a downwardly-inclin'ed"inner kwall 15.v The; cope member. is provided with recesses corre-l spondingto desired projections on the molded objects, asindicated at 16. In this form Fig..4 2. At the instant tliatthe loweimare gin of upper flangev12 passes the upper mail y' gin orflavnge 13 the excess material is espcaping iby passing beneath flange .12 and excess of molding material is placed-in the .mold and the excess amount iseitlier forced. 30

up'between'flangesv 12 land 13 and the smallest arcafof its passageway occurs at tlie'line wardly,jit approaches ange 13 and tlie area of its passageway or the clearance, progres .sively decreases. This decrease in the clearance Causes :an increasing resistance to the flowof the current of escaping excess mate-1 rial. This effect is in addition to the back pressure previously y described and insuresY that the recesses 16 will be properly filled out. A i

constructions may be made by those-skilled inthe art without departingfrom the spirit of'my invention." I 1 c Y Irclaim as my invention: Y

toescape therebetween, theV flange of thev lower 'portionbeing spaced about that of the rupper portion.

Obviously, vmany modifications in" these r Y 1. A mold. comprising n two coperating portions ,having` overlapping flanges ranged to permit excess molding materialv ing yan upstandin'gjange externally 'over- Y lappinga portionfof said cope member'and spaced therefrom. Y:

' 3. A' ila-sh mold comprising a cope member and agdraf member havingco-actmg Il. A mold coi'nprising coperating cope eratiom while causing an Vincreasing resist- Y ance "to such escape in addition to that caused by the dm'nmshingA space between theirmeetmg edges.

5. A flash mold comprising a drag member having an upwardly-extending flange' pro! videdwith an inclined inner wall and a cope member having la downwardly-extending' liange fitting within aforesaid ange so Y flanges.

as to Afleavea clearance space between said 6.' `A flash mold comprising afcl1ca4gg mem-V ber; having an 'upwardly extending'ilange about its edge and. a Vcope/member:having a downwardly extending flange' engaging j.the upper edge, ofthe drag member and spaced apart from and within the flange of V3o the kdragV member. A l 7. A flash mold comprising vrelativelyV movable? cope and drag members landcop erating means earried'lby the meeting. portions of the membersy for'maintainingfa'head 35 'i vof the material beingI molded during the latterpart of the relative 'movement of the members to eXert a back'pressure upon the 'material' inY the mold.

' In' testimony whereof,V 'I have hereuntov l0 subscribed my name this 23rd 'dayf o-fAu- -gust,19l7.

A,"WILLARD KEMPTN- i. i' 

